Tester for fuel delivery system



Nov. 11, 1958 H. H. MORSE 2,859,612

TESTER FOR FUEL DELIVERY SYSTEM Filed oct. 1, 195e V2 shams-snee*v 1 39INVENTOR.

.l HOWARD H. MORSE BY l I6 y /777 l /1/1 l/ lll/M l ATTORNEY H. H. MORSE2,859,612

TESTER FOR FUEL DELIVERY SYSTEM 2 Sheets-Sheet 2 4 T TH fm...

ATTORNEY Nov. 11, 1958 Filed Oct. 1. 1956 United States Patent O2,859,612 TESTER FOR FUEL DELIVERY SYSTEM Howard H. Morse, Portland,Oreg. Application October 1, 1956, Serial No. 613,115 4 Claims. (Cl.713-118) This invention relates to means for testing the delivery systemby which liquid motor fuel for an internal combustion motor,particularly for the motor in an automotive vehicle, is supplied fromthe motor fuel tank.

This application is a continuation-in-part of the pending applicationSerial No. 528,337, filed under date of August 15, 1955, and entitled,Testing Means for Fuel System, 7 and, like the previous application, isconcerned not only with means for testing the performance of the fuelpump in the system but also, and more especially, with the ascertainingof the existence of any air leakage into the system between the fueltank and the pump.

In the device of the present invention, during the course of the testingof the fuel system, the fuel is caused to be delivered into a receptaclehaving a transparent wall so that the delivered fuel in the course ofthe test can be observed for the purpose of detecting any air bubbles inthe same. Any such air bubbles would, of course, indicate an air leaksomewhere along the line on the suction side of the pump. As is wellknown, however, there may be, and generally will be, some vapor bubblesin the delivered fuel, and the problem has been to prevent aninexperienced observer or tester from confusing vapor bubbles with airbubbles.

yIn the device described in the pending application Serial No. 528,337,the air bubbles and the vapor bubbles are caused to follow separatedpaths as they rise to the Vsurface ofthe fuel delivered into thereceptacle of the testing device.

For the fuel delivery systems of most automotive vehicles, underordinary conditions, the

means described in the previous application by which the vaporbubblesand air bubbles are separated will work satisfactorily. However, ininstallations where a large K volume of ow of the fuel takes place andis accompained with the relatively higher vacuum suction necessaryfor'producing a large vvolume ow, the amount of bubbles may be increasedbeyond the capacity of the ldevice ofthe previous application forclearly and accurately separating' the air bubbles from the vaporbubbles.

f 'An object of the present invention accordingly is to provide afurther improvement in such fuel system testing means which will enablethe air bubbles to be sepa rated from the vapor bubbles and to bedischarged from the'delivered fuel in a path entirely by themselves eventhough a large volume tlow of the `fuel takes place into the receptacleof the testing device and even though such delivered fuel carries anexcessive amount of vapor developed as a result of the suction to whichit has been subjected under the action of the fuel pump.

It is a well known fact that, when vapor develops in I liquid fuel, suchas gasoline, as a result of the subjecting of the liquid to suction orpartial vacuum, this vapor can be made to return to liquid state if theliquid fuel and vapor are subjected to sufficiently increased pressure.

A further ,object of the present invention accordingly is to providemeans in a fuel testing device of the type ice indicated whereby thedelivered fuel will be subjected to increased pressure in order that thevapor in the fuel, instead of passing of from the fuel as vapor bubbles,will revert back to a liquid state, thus to a large extent eliminatingthe discharging of vapor bubbles from the fuel under test and in thismanner limit the final discharged bubbles to air bubbles and thus enablethe discharging of air bubbles from the delivered fuel to beunmistakably discerned.

The improved means by which these objects are attained in the testingdevice of the present invention and the manner in which such improvedmeans functions will be explained briey with reference to theaccompanying drawings.

In the drawings:

Figure 1 is an elevation, partly in section, of the entire fuel systemtesting device including the improved means embodying the presentinvention, this gure showing the device in position prior to the specialtesting for air leaks inthe fuel delivery line;

Figure 2 is a corresponding sectional elevation illustrating theemployment ofthe device particularly for testing air leaks in the fueldelivery line as well asfor `making a flow test;

Figure 3 is an enlarged perspective view of a special means or air bellthrough which the principal objects of the present invention areattained; and t Figure4 isa bottom plan view of the air bell portion ofthe device shown in Figure 3.

In Figures l and 2 the transparent glass jar 10 is the receptacle intowhich the fuel is delivered in the testing of the fuel system. Thereceptacle 10 has a circular neck which is formed with threads toaccommodate the threads of a cap 11 which fits n the top of thereceptacle and has sealing engagement with an interposed gasket 12. Thecap has an airvent 11.

The cap 11 is formed with a central downwardly-extending or recessedcylindrical portion -13 which is open at the bottom and terminates in anannular inwardlyextending flange 14. This recessed cylindrical portion13 isI threaded on the inside at the top for engagement with a retainernut 15. t Y

A tube 16 extends down into the receptacle 10, having a sliding t in theretainer nut 15 and also sliding within the ange 14. A spring 22surrounds the tube 16 in the recess 13 ofthe cap 11. The lower end ofthis spring 22 engages a washer 21 located `atthe bottom of the lrecess13, and a suitable sealV 20,-, preferably of neoprene,

is interposed between the washer 21 and the bottom flange 14. The'upperend of the spring 22 engages a steel washer 19 which, in turn, engages asteel spring ring 18 secured in a groove on the tube 16. A ber washer 17is placed between the bottom of the retainer Vnut 15 and the spring ring18. The spring 22 is held under compression at all times between theupper washer 19 and the bottom washer 21, and thus the spring 22normally maintains the tube 16 in the maximum raised position shown inFigure 1 when the device is set up, but permits the tube 16 to be pusheddownwardly a limited distance' with respect to the cap 11 and receptacle10 against the force of spring 22.

A housing 23 (Figure l) is secured on the upper end of the tube 16. Thishousing 23 in turn supports a pressure gauge 24 of standardconstruction, the gauge being connected by a channel with the interiorofthe housing 23. The housing 23 is formed with a transversely extendingpartition 25 which has a central channel 25' connecting the upper andlower portions of the housing 23.

A valve member 27, preferably Yshaped substantially as shown in Figure1, is located inthe lower portion of the housing 23 and is secured tothe top end of a rod 29.

The top end of the tube 16 is beveled so as to form a lower valve seat28 for the valve member 27, and the wall at the bottom of the channel 25in the housing 23 is similarly beveled to form an upper valve seat 26for the valve member 27. A spring 30, located in the upper portion ofthe housing 23 engages the valve member 2.7 for the purpose of normallyholding the valve member 27 down against the lower valve seat 28.

The upper portion of the housing 23 has an inlet port in which the endof a connectingy member 31 is secured. A flexible tube 34 is attached tothe outer end of this connecting member 31 and is adapted to be attachedto the fuel pump 49 when the device is set up. The connecting member 31also houses a rotary'valve 32. The valve 32 is provided withl aregularflow passaeewav 33 and also with a restricted ilow passageway 33'.Normally the valve is positioned as shown in Figure l so that the flowfrom the pump 49 during the testing operation will pass through theregular or unrestricted passageway 33.

The upper portion of housing 23alfso has a corresponding outlet port inwhich a nipple connector 35 is secured. A flexible tube 36 is attachedto the outer end of the nipple 35 and is adapted to be connected to themotor carburetor 50 when the testing device is set up.

The valve rod 29 for the valve member 27 extends downwardly through thetube 16 and extends substantially to the bottom of the transparentreceptacle 10. The tube 16. however. terminates above the bottom of thereceptacle. A suitable guideway 40 (Figure 4) is provided in the lowerportion of the tube 16 so as to keepA the valve rod 29 centered in thetube while permitting relcative movement axially of the tube withrespect to the ro Since the bottom of theV tube 16 is normally spaced ashort distance above the bottom of the receptacle 10 while the valve rod29 extends to the receptacle bottom. it will be apparent from Figure 1that adownward thrust on the housing 23 and tube 16. by causing thelower valve seat 28 to move downwardly away from the valve member 27,will open the valve-controlled entrance from the lower portion of the'housing 23 into the tube 16. Also further downward thrust on the housing23 and the tube 16, rby bringing the upper valve seat 26 into Contactwith the valve member 27, will close the passageway or central channel25' leading from the upper portion of housing 23 to the lower portion.In other words, when the tube 16 is in its normal raised position. asillustrated in Figure l, the valve member 27 will be in its relativelower closed position; when the tube 16 and with it the housing 23 1sthrust downward a slight distance, against the force of spring 22 andalso-the force of spring 30. the Valve member will be in its relativeopen position illustrated in Figure 2: and when the tube 16 and housing23 are thrust a sufficient distance downwardly the valve member 27 willbe in its relative upper closed position. The purpose for providing forthese relative changes of valve position will be presently apparent.

The housing 23 is provided with a second outlet port 41 in which an endof a connecting member 42 is secured. A flexible discharging tube orhose 44 is attached to the outer end of member 42, and, when the testdevice is set up, the free end of the hose 44 is inserted in the llerneck of the fuel tank of the motor. The connecting member 42 houses ashut-olf valve 43 which is kept closed at all times except at thetermination of the test, as later explained.

A cylindrical housing, designated as a whole by the reference character37 which serves inY part as an air chamber, and which, for want of .abetter term, is referred to as an air bell, is rigidly secured at itstop of the tube 16. The top of this air bell 37 is closed and isairtight, having an airtight connection with the tube 16. The bottom ofthis air bell is entirely open and is located approximately in the samehorizontal plane as the bottom end of the tube 16. As indicated in thedrawings, the inside 4 diameter of the air bell 37 is considerablygreater than the outside diameter of the tube 16 and preferably isseveral times greater.

An air outlet tube 38 is mounted in the air bell 37 being locatedpreferably about two-thirds of the distance from the top to the bottomof the air bell and this outlet tube 38 extends horizontally through thewall of the air bell and terminates on the outside a short distance fromthe cylindrical wall of the air bell. The outer end of this outlet tubepreferably is cut o obliquely as shown at 33', thus giving an obliqueupward slope to the end of the tube. Inside the air bell the tube 3S isformed with a downwardly-extending U-shaped portion 39. the top of whichis located approximately in the same horizontal plane as the outsideportion of the tube.

When the device is set up and connected in the manner described and asillustrated in Figure l, and thus with the valve 32 in the flow linefrom the pump 49 having its main passageway open, with the valve 43closed, and with the valve member 27 engaging the lower valve seat 28and thus closing the entrance into the tube 16, the motor and fuel pumpare operated and the pressure on the gauge 24 noted. The motor and pumpare then stopped and the gauge observed. If the gauge pressure dropstowards zero this would indicate a leak either at the discharge checkvalve of the pump 49 or at the needle and seat ofthe carburetor 50. Thelocation of such leak is determined by again operating the motor andpump to bring the gauge up to the preceding reading, then stopping themotor and pump and pinching or clamping one ofthe exible tubes 34 or 36,momentarily preventing any passing of fuel therethrough, and observingthe gauge. Thus, for example, if the tube 34 is closed in this mannerand the gauge pressure drops, this will indicate a leak in thecarburetor 50, whereas if the gauge pressure does not drop under suchcircumstances this will indicate that the leak is in the pump. v

Assuming that there is no leak either in the carburetor or in the pump,the next step in the test would be to test the pump performance. Forthis purpose the motor and pump are again started and the tube 16,housing 23 and Vgauge 24 are pressed downwardly with respect to thereceptacle 10 until the valve member 27 is caused to be in the relativemiddle or neutral position illustrated in Figure 2, in which case thefuel delivered by the pump will pass down through the -tube 16 and intothe receptacle 10.

The transparent wall of the receptacle 10 is provided with suitablevolume indicating markings, such as the lines A, B and C, the lowestline being the starting level for the ow test and the lines B and Carranged to indicate proper volume flow for small and large pumpsrespectively during the prescribed period of time (for example, during45 seconds at 500 R. P. M. engine speed). The moment the housing 23, andtube 16 are released and allowed to return to the normal raised positionof Figure 1 the tlow of the fuel down into the tube 16 and into thereceptacle 10 will be shut off.

As the fuel passes down the tube 16 into the receptacle 10 and the levelof the liquid begins to rise in the receptacle the air in the air bellbecome'srentrapped therein. Also any air in the fuel which leaves thedischarging bottom end of the tube 16 will pass up into the bell andjoin the air in the upper portion of the bell. As a result, both of therise in the level of the liquid fuel in the receptacle and of thedelivery of air into the air bell (assuming that there is an air leakalong the fuel delivery line), the pressure of the confined air withinthe air bell will increase, and the level of the uid within the air bellwill be lower than the fluid level on the outside of the air bell.

Let it be assumed that the level of the liquid fuel in the receptacle 10on the outside of the air bell has risen above the height of the outlet38' of the outlet air tube 38. In such case, not only will the airwithin the air bell be under pr'essfur'efhut, since thelevel of the:liquid fuel in the lower portion of the air bell will bebelow the levelon the outside of the air bell, thel pressure at the 10.through the tube16, the delivered fuel carries fuel vapor (resulting from the suction"or partial vacuum to which the liquid fuel was subjected while beingdrawn by the pump from'the fuel tank) andalso carries air. Then therewill be both vapor bubbles and air bubbles emitted from the bottom endof the tube`16 which will move upwardly in the fuel in the bottomportion'of the air bell. However, as far as the vapor bubbles areconcerned, since the pressure to which the liquid fuel in the air bellis subjected is greater than atmospheric pressure, and since it is wellknown that the vapor in such fuel will return to liquid state when thefuel carrying the vapor is pressurized,l these vapor bubbles will tendto return to liquid and thus disappear under the` pressure of the liquidwithin the air bell. On the other hand, regardless of the air pressurein the air bell, the air in the fuel discharged from the bottom of thetube 16 will continue to pass up as air bubbles through the liquid inthe air bell and join the pressurized air above the liquid. Then, as thevolume of air within the air bell is built, up in this manner, theexcess air will be forced out through the tube 38, with the result thatair bubbles will be discharged from the outlet end 38 and be clearlydiscernible by the observer.

As the level of the liquid in the receptacle continues to rise and theair pressure within the air bell, and the pressure on the liquid in thelower portion of the air bell continues to increase, there will belittle, if any, likelihood of fuel vapor being discharged from the tube38 but, with the continued increase in the volume of air in the air bellsome air must, of necessity, be discharged through the outlet tube 38and thus indicate the fact that air is being drawn into the fuelsomewhere along the fuel line, the ascertaining of which fact is thepurpose of this portion of the test.

The relative size of the air bell will, of course, depend upon thevolume ow inthe fuel delivery system to be tested and the generalconditions under which the testing is performed, and obviously thedevice can be made so as to test adequately any size volume flow. I havefound, however, that an air bell up to 3 inches in diameter and up to 6inches in height will be large enough for the testing of the fueldelivery system in any ordinary automotive vehicle and under all normalconditions of operation.

In addition to testing the pump performance and to the special test forair leaks on the suction side of the pump and in the fuel line leadingfrom the fuel storage tank to the pump, it may be desired to test theflow when the ow is restricted, inasmuch as mechanical fuel pumps withcheck valves must operate against a pressure in actual use. This testingis done by rotating the valve 32 (Figure 1) 90 until the smallerrestricting passageway 33 connects the pump with the testing device. Thetest for restricted ow can then be made in the same way as the ow testpreviously described.

When the entire test is completed it is desirable to return the fuel,which has been collected in the receptacle 10, to the fuel storage tankfor the motor. With the end of the hose 44 inserted in the filling neckof the fuel storage tank the valve 43 is opened and the housing 23 isallowed momentarily to return to raised position in order to close theentrance into the top of tube 16. A ow of fuel from the pump will thentake place through the housing 23, valve 43, and hose 44 to the fueltank. Then the housing 23 is pushed all the way down in order to causethe valve member 27 to close the passageway 25 completely. This normallywill cause a siphoning action to be set up (since the receptacle 10 willbe at a higher elevation than the fuel storage tank), and this willcontinue until the receptacle 10 has been emptied, provided the housing23 is kept constantly pushed down. Should there not be enough flow fromthe pump to start this siphoning action, the Siphon can be started byapplying a slight amount of air pressure to the air vent 11 in the capof the receptacle.

I claim:

l. In a fuel system tester of the character described, including afuel-receiving receptacle'having a transparent wall, a delivery .tubeextending substantially vertically down into said receptacle with thebottom end of said tube spaced a short distance from the bottom of saidreceptacle, and means for delivering fuel through said tube into saidreceptacle, an air bell surrounding said tube in said receptacle, thebottom of said air bell being open and spaced slightly above the bottomof said receptacle, the remaining portion of said air bell beingairtight, an air outlet tube extending outwardly through the wall ofsaid air Abell and terminating in said receptacle a short distance fromsaid air bell, said outlet tube being located more than half way betweenthe top and the bottom of said air bell wall whereby, with the deliveryof liquid fuel into said receptacle through said delivery tube, airpressure will be built up in the upper portion of said air bell andultimately the delivery of any air with said fuel will cause air to bedischarged from said outlet into the liquid fuel outside of said airbell while vapor in said delivered fuel will be subjected to liquifyingpressure in the bottom of said air bell.

2. In a fuel system tester of the character described, including afuel-receiving receptacle having a transparent wall, a delivery tubeextending substantially vertically down into said receptacle with thebottom end of said tube spaced a short distance from the bottom of saidreceptacle, and means for delivering fuel through said tube into saidreceptacle, a cylindrical air bell surrounding said tube in saidreceptacle and co-axial with said tube, the bottom of said air bellbeing open and spaced slightly above the bottom of said receptacle, theremaining portion of said air bell being airtight, the interior diameterof said air bell being considerably greater than the external diameterof said tube, an air outlet tube extending outwardly substantiallyhorizontally through the cylindrical wall of said air bell andterminating in said receptacle a short distance from said air bell, saidoutlet tube being located below the middle point of said cylindricalwall of said air bell, whereby, with the delivery of liquid fuel intosaid receptacle through said delivery tube, air pressure will be builtup in the upper portion of said air bell and ultimately the delivery ofany air with said fuel will cause air to be discharged from said outletinto the liquid fuel outside of said air bell while vapor in saiddelivered fuel will be subjected to liquifying pressure in the bottom ofsaid air bell.

3. In a fuel system tester of the character described, including afuel-receiving receptacle having a transparent wall, a delivery tubeextending substantially vertically down into said receptacle with thebottom end of said tube spaced a short distance from the bottom of saidreceptavle, and means for delivering fuel through said tube into saidreceptacle, an air bell carried on said tube in said receptacle, thebottom-of said air bell being open and located approximately in the samehorizontal plane as the bottom of said tube, the remaining portion ofsaid air bell being airtight, an air outlet pipe extending outwardlythrough the wall of said air bell and terminating in said receptacle ashort distance hom said air bell, said outlet pipe being located atapproximately two thirds of the distance between the top and bottom ofsaid air bell, said outlet pipe within said air bell having adownwardly-extending'U-shaped portion whereby, with the delivery ofVliquid fuel into said receptacle through said delivery tube, airpressure willlbe built up in the upper portion of said air bell andultimately the delivery'of any air with saidfuel will cause air to bedischarged from said outlet pipe into the liquid fuel outside of saidair bell while vapor in said delivered fuel will be subjected toliquifying pressure in the bottom of said air bell.

4. Ina fuel system tester of the character described, including afuel-receiving receptacle having a transparent wall, a delivery tubeextending substantially vertically down' into said receptacle with thebottom endof said being airtight, kthe interior diameter of said airbell being considerably greater than the external diameter of said tube,an air outlet pipeV extending outwardly substantiallyhorizontally-through the cylindricaly wall `of saidair bell andterminating in said receptacle a'short distance ,froml saidair bell, theouter end of said outlet pipe having an oblique upward slope, Asaidoutlet pipe withinsaid air vbell having a downwardly-extending U- shapedportionwhereby,with the delivery -ofliquid fuel into said receptaclethrough Ysaid delivery tube, air pressure will be built lup inthe upperportion of said air bell and ultimately the delivery of any air withsaid fuel will cause air to be discharged from said outlet pipe into theliquidfuel outside of said air bell while vapor in said deliveredfuelrwill be subjected to liquifying pressure in the bottom of saidA airbell. v

References `Cited in the le of this patent UNITED STATES PATENTS

